US2192021A - Automatic braking system - Google Patents

Description

Feb. 27,1940. w. WEEKS AUTOMATIC BRAKING SYSTEM Filed Jan. 24, 1939 4 Sheets-Sheet 1 hox INVENTOR. WA BEEN I.

WEE/ 5 v ATTORNEYS ;Feb. 27, 1940.

w. l. WEEKS AUTOMATIC BRAKING s sum Fild Jan. 24, 1959 4 Sheets-Sheet 2 INVENTOR.

WAEEENZ WEEKS- Feb. 27, 1940.

w. 1. WEEKS AUTOMATIC BRAKING SYSTEM 4 Sheets-Sheet 3 Filed Jan. 24, 1939 MN m M m I A .k

M WW w MN \duj 27 2 4% M Feb. 27, 1940. w, WEEKS 2,192,021

AUTOMATI C BRAKING SYSTEM Filed Jan. 24, 1939 4 Sheets-Sheet 4 Egg 5.

. I v 120 H9 H5 INVENTOR. WARRENI. WEEKS 4 6/1 ATTORNEYS Patented Feb. 27, 1940 UNITED STATES PATENT OFFICE AUTOMATIC BRAKING SYSTEM Warren I. Weeks, Ventnor, N. J.

Application January 24, 1939, Serial No. 252,541

14- Claims.

My invention relates to automatic operating mechanism for setting the brakes of an automobile in the event an operator of the vehicle should become unconscious through any cause or should fall asleep causing him to release his grip on the steering wheel breaking the contacts of a switch therein and automatically setting the brakes of the vehicle.

In the past, automatic braking systems with which I am familiar, were not fully practical since upon the release of the operators grasp from the steering wheel, powerwas applied to the braking system, the intensity of the same not being automatically governed in relation to w the speed at which the vehicle was travelling.

The engine was stopped when thebrakes were applied regardless of whether the stop was an unconscious or conscious one.

Other automatic braking systems were not designed to be connected or disconnected from the conventional braking system of a vehicle quickly and simply; No means in these prior systems were provided to lock the brakes after the setting thereof and upon the stopping of the engine of the vehicle.

It is, therefore, among I vention to provide 'a mechanism whereby the vehicle is automatically 'brought to a stop when the operator releases his grip from the steering wheel.

It is another object of my invention to provide an automatic braking system for a motor vehicle wherein the intensity of the braking is automatically controlled to provide the proper amount of brakingpower at high and, low speeds of the vehicle. A

Another ob ct of my invention is toprovide means wher bythe maximum amount of braking powe 40 after the brakes are set automatically or by foot vt hen the ignition of the vehicle is cut and the engines stopped. 7

A still further object of my invention is to provide means to manually control the intensity 5' of the braking power in order that the proper amount of power may be applied to the brakes when a vehicle is loaded or when the vehicle is empty.

Another object of this invention is to provide vacuum controlled locking means to lock the brakes, so'that the same cannot easily be released after the same are applied without starting the engine of the vehicle.

It is still a further object of my invention to provide an automatic brake operating mechathe objects of my in-- s applied to the brakes of the vehicle -nism for a motor vehicle which may be easily attached to the braking system of vehicles already in use as well as new vehicles regardless of type of brake system.

A further object of this invention is to provide an automatic braking system which does not interfere with the conventional operation of the brakes of a motor vehicle by nieans of the conventional foot brake pedal.

It is a further object of my invention to provide for the automatic cut-out of the ignition circuit of the automobile upon the release of the operator's grip from the steering wheel. Means, however, are also provided whereby the automatic ignition cut-out means may be manually disconnected from the remainder of the automatic braking system without affecting the operation of the system.

It is still a further object of my invention to provide means whereby the operator of a motor vehicle may consciously apply the brakes 0f the vehicle through the automatic braking system of my invention without cutting out the ignition to the engine.

Other objects will be obvious or will appear during the course of the following specification.

In accomplishing the above objects, it has been found most satisfactory, according to this embodiment of the invention, to provide an electrically,controlled valve having three ports, two of which are connected to two vacuum intensity valves, one ofsaid valves set at a fixed position governing the vacuum tobe admitted to the power brake cylinder through the third port to a second electrically controlled valve in accordance with the speed of the vehicle. The other vacuum intensity valve, which is adjustable manually from the driving compartment 01' the vehicle, is adapted to admit vacuum of the proper intensity to the power brake cylinder, through the second electrically controlled valve, in accordance with whether, or not the vehicle is loaded. or empty.

The first-mentioned electricallycontrolled valve is controlled by an electrical governor which is set to become inoperative above a' certain fixed speed which sets the first-mentioned electrically controlled valve in a position-to admit vacuum, through the vacuum intensity valve which is manually controlled from the driving compartment in accordance with whether or not the vehicle is empty or loaded, to the second-mentioned electrically controlled valve.

When the vehicle is being operated at a speed at or less than that to'which the electrical governor is set, the electrical governor is in an operative position and the first-mentioned electrically controlled valve is set to admit vacuum to the second-mentioned electrically controlled valve through the .vacuum intensity valve which is set at a fixed position. This fixed position is set in relation to the speed at which the electrical governor is set to operate, so that while said governor is in an operative position the proper amount of vacuum is passed through the intensity valve to stop the vehicle smoothly at or below the speed at which the governor is set to operate.

Thesecond-mentioned: electrically controlled valve iscontrolled through the switch mechanism in the steering wheel so that vacuum will be admitted to the power brake cylinder uponthe release of the operator's grip from the steering wheel. The intensity of the vacuum admit-. ted to the power brake cylinder is, of course, governed by whether or not the electrical governor is operative or inoperative.

A vacuum controlled locking device to act upon the power brake shaft is connected to the intake manifold of the engine so that the same will lock said shaft locking the brakes after the same have been applied and the vacuum in the engine stopped by the engine being cut 01!.

Means are also provided which are operated by movement of the power brake shaft by the cylin- -der so as to disconnect a switch which cuts out the ignition of the automobile stopping the engine. This means is so connected to the clutch pedal through a flexible connection that upon depressing the clutch this switch becomes inoperative and the engine is not stopped by applying the brakes through the automatic system. A switch is also provided to manually disconnect the ignition cut-out switch in the event it is not desired to use the same in the automatic system.

Connections between the brake pedal and the master hydraulic cylinder for applying the brakes are provided whereby the brakes of the vehicle may be applied-by foot. Means cooperating with the foot brake pedal are provided to operate a switch which renders the automatic braking system inoperative when the vehicle brakes are applied in the conventional manner.

7 Switch means are also provided, as-- well as a. valve in the main vacuum line leading to the intakemanifold of the engine, whereby the autopossible embodiments to which the invention vis by no means restricted, the drawings being merely by way of illustration and not by way of limitak system.

Figure 2 isa vertical cross-sectional view of the main vacuum control valve used in conjunction with the vacuum power'cylinder.

Figure 3 is a cross-sectional view taken on the line 3-3 of Figure 2.

Figure 4 is a vertical cross-sectional view of the secondaryvacuum control valve used in my automatic control system.-

Figure 5 is a cross-sectional view of my vacuum controlled locking device which acts on the powe brake shaft. 7

, Figure 6 is a cross-sectional view taken on the line 8-3of Figure 5. v

Like numerals refer to like parts throughout the several views.

In Figures 1 and 1a of the drawings is shown I 1 Rotatably mounted within the shaft I3 is a shaft 15 it upon which is fixedly mounted a clutch pedal A pin I8 is mounted on the extension l2 and projects through a slot I! in a clevis l8, one end of which is pivotally connected to a lever l9 which is, in turn,pivota1ly mounted at 19a and connected to a piston rod 20 on a piston in the hydraulic master cylinder 2|.

The other end of the clevis I8 is pivotally connected to an arm 22 one end of which is, in turn, 26 pivotally connected to a mounting 23 anchored to the frame (not shown) of a vehicle. The'arm 22 g has a plurality of apertures 24, to provide an adjustment for the connecting rod 25 in order to increase or decrease the braking powerby changing the leverage thereof.

The connecting rod 25 is connected to a clevis 26 by means of a pin 28 extending through the clevis. The clevis 26 is fastened to the power brake shaft 29 which is, in turn, connected to a.

piston in a vacuum cylinder 30. The vacuum cylinder 30 is a part of my automatic braldngsystem which is hereinafter described.-

v The extension l2 of the brake pedal II is connected to a movable arm 3| attached tothe movo able contact of a switch 32 through a connecting rod 33. One contact of said switch is connected to the ground through the lead 34 and the other contact is connected .to one contact of a main control valve 33 also a partof my automatic braking system, which will be hereinafter fully described, and to one contact of the switch in the steering wheel l3 through the lead 36, steering wheel cut-out switch 31 and lead 33. The contacts in the steering wheel switch are normally 0 spaced a K When it is desired to use the foot brake in a conventional manner, apart from the automotive braking system, pressure is applied to the brake pedal II which rocks the extension l2. which,

' through the pin l3 bearing on one end of the slot H in the clevis l3, causing the clevis to move. to the left which, in turn, moves the lever I! to pivot at I91: and move the piston in the master hydraulic cylinder 2|. Movement of the piston in the master cylinder 2| inwardly applies pressure to the hydraulic system, which pressure is effective to apply the brakeson the individualwheels of a vehicle. Rocking of the extension l2 will also move the connecting rod 33 which will 55 make a contact between the two controls in the switch 32 rendering the automatic system inoperative as will be hereinafter described.

Supplementing this hydraulic foot operated braking system I provide an automatic operator which is effective upon release of the .operators grip from the steering wheel.

This automatic system comprises the vacuum cylinder 30 which is connected to a main control valve 35 through a pipe line 40. The main contight.

trol valve 95, as shown more particularly in Figures 2 and 3, consists of two sections, A a solenoid and B the valve proper. The solenoid section'A houses the solenoid coil 4| one end of which is connected to one pole of a battery 42, the other pole thereof being grounded, through the leads 43 and 44. The other end of the solenoid coil 4| is connected to the opposite pole of the electrical source through the leads 45, 36, steering wheel cut-out switch 31, lead 39 and the switch in the steering wheel l9, one contact of which is grounded at l9a.

The section B of the mam control valve 35 consists of a body portion 35a having a recess 46 in the top central portion thereof. The recess 46 is screw threaded to accommodate a plug 41 which divides said recess into a top chamber 49 and bottom chamber 49. The chamber 49 has an opening 59 therein and the chamber 49 has an opening 5|, as shown more particularly in Fig-' ure 3. I

The bottom of the body portion 35a has a recess 52 therein which has an opening 53 connected to an air cleaner 54. The solenoid coil 4| is mounted in a casing 55 which, in. turn is mounted on the bottom of the body portion 35a in such a manner as to make the recess 52 air The chamber 49 and the recess 52 are connected by means of a passage 56. The passage 56 has an opening 51 therein.

The recess 46 is closed at the top by a plate 59 having a passage 59. A vacuum head 69 is mounted ontop of the plate 59 said head having a chamber 6| in which is mounted a flexible diaphragm 62. The top portion of the chamber 6| has an opening 63' and the bottom portion 6|a has a gutter 64a extending around the surface of the bottom in which there is a plurality of exhaust apertures 64 therein. The gutter 64a acts as a drain for any oilwhich may enter the exhaust apertures, so that said oil will not come in contact with the diaphragms 62 and 66 and disintegrate the same. The top portion of the chamber 6| and the bottom portion 6|a are in airtight relation to one another. A second air tight chamber 65 is formed by a flexible diaphragm 66. The flexible diaphragms 62 and 66 are connected by means of a rod 61 which extends through the passage 59 in the plate 59 and has a valve 69 which cooperates with the passage 59 to open and close the same as is hereinafter described. The chamber 65 is connected with the opening 5| in the body portion 35a by means of a passage 69 in said body portion, as shown in Figure 3, which communicates with a passage 19 in the plate 59.

The armature H of the solenoid 4| is connected to a valve stem 12 which extends through the passage 56. A valve 13 is mounted on said stem to open and close communication between the passage 56 and the recess 52. Another valve I4.

the opening andv closing of the valves I3 and I4.

(See Figures 1 and 1a.) The opening 69 01' the chamber 6| is connected to the intake manifold nccted into said line by means of a pipe 19. The auxiliary reservoir 11 has a petcock 11a therein in order that the vacuum in the system may be released therethrough. Interposed between said auxiliary reservoir and said intake manifold is a check valve 19 so that in the event the automobile engine is stopped the source of vacuumsupply in the reservoir 71 will not be lost. A valve 99 is interposed in the line 16 between the check valve 19 and the intake manifold in order that the automatic system may be cut oil by turning the valve 99 to the off position, turning the petcock 11a to an open position, and turning the switch 31, so that the contacts therein are broken and r the switch in the steering wheel |9 made inopermechanism of my invention whereby the intensity of the braking power may be increased automatically at a speed in excess of a predetermined speed and whereby the braking intensity might also be increased or decreased manually in accordance with the load carried by the vehicle.

(See Figure 4.) Such a means consists of a secondary control valve 9|, which comprises two sections, C a solenoid and D the valve proper. The solenoid section C houses a solenoid coil 82 one end of which is connected to the secondary side of a conventional ignition switch 93 through the lead 84, so that there will be no loss of current when the ignition switch is open. The other end of said solenoid coil 92 is connected to one contact of an electrical governor 95 by means of the lead 96.

The electrical governor 95 is of the conventional type and is set so that the contacts thereinwill snap apart or break at a fixed predetermined speed. For example, the governor which I use in the embodiment of my invention, shown in the drawings, is set so that the contacts therein will remain together at or below a speed of 18 miles per hour. At any speed over 18 miles per hour, the contacts therein will snap apart and remain open. The other contact of the electrical governor 85 is connected to the ground through the lead 91. See Figure 1.)

(See Figure 4.) The section D of the secondary control valve 8| consists of a body portion having a recess 89 in the top thereof which is screw threaded to accommodate a plug 99 which, when screwed into the recess 99, forms a chamber 99 therein. The plug 89 has a threaded opening 9| therein which communicates with the chamber 99 through a passage 92. In the bottom portion of said secondary valve is formed a recess which communicates with the chamber 99 through a passage 94. The passage 94 has an opening 95 therein.

.The solenoid coil 02, which is mounted in a housing 96, is mounted on the bottom of the section D closing the recess 99 and making the same air tight. The recess 93 has a screw threaded opening 91 therein.

A valve stem 99 is fastened to an armature 99 in the solenoid coil 92 which valve stem extends through the passage 94. A valve I99 is mounted on the end of the valve stem 99 and is adapted to open and close communication between the passage 94 and the chamber 99. A valve |9| is also mounted on the valve stem 99 to open and close the communication between the passage 94 and the recess 93. The valves I99 and IM are so mounted on the valve stem 99 that, when the solenoid 92 is de-energized, the communication between the chamber 99 and the passage 94 is open and the communication between the passage 94 and the recess 93 is closed. When the solenoid 82 is energized the communication between the chamber 90 and the passage 94 is closed and the communication between thepas sage 94' and the recess 93 is open.

'-(See Figures 1 and 1a.) The secondary control valve M is connected to the main control valve 35 by means of a pipe line I02 which is connected to the opening 95 in the secondary control valve BI and the opening in the main controlvalve 35. The opening 9| in the control valve 8| is connected to a vacuum intensity con trol valve I03 through the pipe line I04. The vacuum intensity control valve I03 is adapted to be operated from a control lever I05 in the drivers compartment of a vehicle and is con nected to said lever through the lever I06 on said valve by means of a cable I01 in a'conduit I01a. The valve I03 is connected to the intake manifold of the engine through the pipe line I08, 16,

and the check valve 19 and valve 80. The valves I 19 and 80 are interposed between the intake manifold and the vacuum intensity control valve.

The auxiliary reservoir 11 is interposed in the line 16 between said check valve and the load control valve I 03.

The valve I03 is to regulate manually the intensity of the braking'power, so that with an empty vehicle the operator will have sufficient braking power to makea satisfactory stop, and so that with a loaded vehicle there will be increased braking power. The valve I03 is graduated from a minimum to a maximum braking power and controls the braking power in the automatic system of my invention when the speed of the vehicle is above the predetermined speed fixed by the governor 85.

The opening 91 in the secondary control valve 8I is connected to a secondary vacuum intensity control valve I09 through a pipe line IIO, which valve I09 is, in turn, connected through the pipe line III to the line 16.

The secondary vacuum intensity control valve I09 is setat a predetermined position in order that the proper amount of braking power below a certain speed, which is governed by the governor 85, is accomplished.

In order that the brakes of the vehicle may be looked after being applied, and after the ignition circuit is closed, shutting off the motor of the vehicle, and the suction from the intake manifold is stopped, I provide a vacuum locking device I I2 which acts upon the power brake shaft 29.

I (See Figures 5 and 6.) The locking device I I2, as shown more particularly in Figures 5 and 6, vconsists of a main body portion havinga recess II 3 forme in the top thereof and a recess I I4 extending through the central portion thereof. A fie ble diaphragm I I5 is mounted in the recess H3 1' miing a chamber H6 and is held in position by a plate II1 which is fastened to the body portion of the locking device II2 making the chamber II6 'air tight. The plate II1 has an opening II8 therein which communicates with the chamber- II6. Fastened tothe flexible diaphragm I I5 by means of a bolt II9 which cooperates with two reinforcing plates I and I2| on said diaphragm is a cam I22 having a curved surface I23 which is adapted to be reciprocated vertically within the recess H4. The curved surface I23 of the cam I22 is adapted to engage a rocker arm I24 which is adapted to rock on a fulcrum bar I25 in therecess 4.

The rocker arm I 29 has a hole I26 passing therethrough which is of a slightly greater diameter than the power brake shaft 29 which passes through holes I21 and I28 on opposite sides of the recess H4 and through the hole I26 in the rocker arm. A boot I29 around the shaft 29 prevents dirt from entering the locking device on'one side of the same while a covering I30 serves a like purpose on the other side. The covering I30 also serves to anchor the locking device to the power cylinder 30. An opening I30a is positioned on the bottom of the covering I 30 closely adjacent the power cylinder 30 to prevent'oil from the locking device II2 entering the power cylinder.

The opening H8 is connected to the intake manifold of an automobile engine through the pipe line I3I which connects to the line 15.

When the motor is not running the locking device will be in the position shown in Figures 5 and 6 with the diagonally opposite edges of the hole I26 in the rocking arm I24 wedged against the power shaft 29, preventing movement there-- of to the right. When the engine is started and the diaphragm I20 moves upwardly through the vacuum created in the chamber II6, the curved surface I23 on the cam I22, which is fastened to the diaphragm, engages the rocker arm. I24 rocking the same on the fulcrum. bar I25 so that the diagonally opposite edges of the hole I26 will disengage the shaft 29 and allow movement of the shaft 29 to the right in order that the brakes might be released. A lubricating tube I33 is provided for lubricating the interior of the locking device.

If, for any reason, the engine should. fail and it is necessary to tow the vehicle, since the looking device II 2 is engaged with the shaft 29 preventing movement of the same, it is necessary to provide means for releasing the locking device. I, therefore, provide a screw I32 in the locking device II2, which acts on the reinforcing plate I2I of the diaphragm II5. By turning the screw inwardly the diaphragm H5 is lifted which will disengage the diagonally opposite edges of the hole I26 from the shaft 29 placing the locking device II2 in an inactive position, so that the brakes can be operated.

When the engine is stopped and the locking device M2 is engaged with the shaft 29, the brakes cannot be released accidentally, such as by children playing in the drivers compartment, since the engine must be started to release the locking device, or the screw 48 which is inaccessible from the driver's compartmentmust be turned to release the locking device.

It is desirable, when the car comes to an emergency stop by means of the operation of the automatic braking device of my invention through the releasing of the grasp of the operator on the steering wheel I0, for example. by the operator lapsing into unconsciousness, to cut the ignition to the motor, so. that the motor will not be left running.

(See Figures 1 and 1a.) by means of a switch I34 which has two fixed contacts one of which is connected to one pole of the battery 42 by means of the lead 44 and the other of which is connected to a normally open cut-out switch-I by means of the lead I36. The ignition of the vehicle is normally connected to the battery 42 through a lead 83a, the

conventional ignition switch 83, leads I31 and I36, and switch 134 and the lead 44.

Themovable contact in switch I34 is con- 75 This -I accomplish nected to a rod I34a, the fixed contacts being normally closed by the movable contact. The rod I34a is adapted to reciprocate horizontally and is pivoted to a lever I39. An arm I40 fastened to shaft 29 is adapted to engage the lever I39 against the switch I34 engages the two fixed contacts.

On the lever I39 closely adjacent the switch I34 is pivotally mounted a lever I42, the lever I42 having a cross-arm I43 pivotally mounted thereon. One end of the cross arm I43 is fastened to a crank I44 on the clutch pedal shaft I45 by means of a flexible connection I46. The other end of the cross arm I43 is fastened by meansof a flexible connection I41 to the rod 33, which is fastened to the arm 3I connected to the movable contact of the switch 32.

When the brakes are applied during an emergency stop through the automatic system of my invention the power shaft 29 moves to the left, as shown in Figure 1, moving the arm I40 to the left also. The lever I39, throughthe tension in the spring MI, is kept in engagement with the arm I40. The arm I42 is held in position, however, through the cross-arm I 43 and the flexible connections I46 and I41. When the lever I39 engages a stop I48, which is anchored'to the frame of the vehicle, the lever I39 pivots on the stop I48 moving the rod I34a, to which-the movable contact in the switch I34 is fastened, to the right, in Figure 1, breaking the contact between the fixed contacts in said switch and thereby cutting off the ignition to the engine.

When a conscious, as distinguished from an emergency stop is made, the clutch pedal is depressed, sothat the crank I44 will move to the left, Figure la, moving the flexible connection I46 to the left, which allows the lever I42 to move to the left with the arm I39 which is in engagement with the shaft 29 through the arm I40. When the brakes of the .vehicle are applied the shaft 29 moves to-the left, the lever I39 moving with it undert'ension of the spring I4I, the lever I39 pivoting on the pivotal connection between itself and the rod I34a. In this manner, the connection between the ignition of the vehicle and the battery 42 through the lead 44, switch I34, leads I36 and I31,'ignition switch 83 and lead 830. is not interrupted since the contactsin theswitch I34 are not broken. The engine of the ISO vehicle, therefore, is not stopped.

(See Figures 1 and 1a.) In using the automatic braking system of my invention in conjunction with the braking system of a motor vehicle to which this system is attached, the cut-out switch 31 is closed which connects one contact of the.

switch in the steering wheel I0 to one end of i the solenoid coil M of the main control valve 35 through the lead 38, switch 31, lead 36, and

lead 45 and also to one contact of the normally open switch 32 which is operated to be closed by the foot brake pedal II. The other contact of the switch 'in the steering wheel I0 is connected to the ground, as is the other fixed contact of the switch 32., The conventional ignition switch 83 is also closed which connects one end of the solenoid coil 82 in the secondarycontrol valve to the battery 42 through the lead 84, switch 03, lead I31, lead I36, the normally closed switch I34, and lead 44. The other end of the solenoid coil H of the main control valve 35 is also con nected to the battery 42 through the lead 44 and lead 43. i

The other end of the solenoid coil 82 of the secondary control valve BI is connected to the governor 85, which is normally closed until a predetermined fixed speed is reached by the vehicle, through the lead 86. The other connection to the governor 85 is grounded through the lead 81.

When the engine of the automobile is started, creating a vacuum in the system, suction will travel from the intake manifold through the pipe 15 andenter the chamber II6 of the locking device II2 which lifts the flexible diaphragm II5 upwardly, raising the cam I22, which rocks the arm I24, unlocking the lock on the power brake shaft 29. (See Figures 5 and 6.) The brakes of the vehicle, however, remain on, so long as the steering wheel I0 is not grasped, since the vacuum in the system created by starting the engine raises the flexible diaphragm 62 in the vacuum head 0f the main control valve 35 through the vacuum created in the chamber 6| by means of suction in the intake manifold. The vacuum acts on said diaphragm through the pipe line 15 which enters the vacuum head 60 through the opening 63. This seats valve 68 against the passage 59. The relation of parts in the main control valve, when the engine is started and before the steering wheel is grasped, is shown in Figures 2 and 3.

After the motor is started and the driver wishes the vehicle to proceed, he grasps the steering wheel I0 which closes the switch therein. The closing of the switch energizes the solenoid coil 4I in the main control valve 35, the electrical current flowing from the battery 42 through the lead 44, lead 43, solenoid coil 4|, leads 45 and 36, switch 31, lead 30, the switch in the steering wheel I9, thence to the ground I0a. The energizing of the solenoid coil 4| in the main control valve 35 causes the armature ,1I to move downwardly, seating the valve 14 against the passage 56 and unseating the valve 13 from said passage, which turn, moves the connecting rod 25 to the right,

which operates the piston in the master hydraulic cylinder 2! so as to release the brakes through the clevis I0, arm I9, and piston rod 20. The vacuum created in the system through the starting of the engine seats the valve 68 against the passage 59 closing the same. The brakeson the vehicle are now in a released position. Y

If the vehicle isloaded, the vacuum intensity control valve I03 is set to allow a maximum amount of vacuum to pass through the same, the

setting being made by means of the control lever I05, which is connected to the valve I03 by means ofthe flexible connection I01. Should the vehicle be empty, the intensity control valve is likewise set so that a minimum amount of vacuum 84 which is connected to one end of the said solenoid coil, the other end of this coil being connected to the governor 85 through the lead 86, said governor being grounded through the lead 81. The energizing of the coil 82 will move the armature therein downwardly setting the valve I00 against the opening of the passage 94, closing the same and unseating the valve IOI from said passage, opening this passage to the recess 93 and the opening therein 91 which is connected to the pipe line I I0, leading from the vacuum intensity control valve I09 which is set at a predetermined fixed position, so that it will admit the proper amount of vacuum into the secondary control valve 8| for setting the brakes at the speed to which the governor 85 is set or a lower speed in order that the brakes on the vehicle will not be applied too forcefully.

For sake of example, we shall presume that the contact in the governor 85 is set so that the same will be broken at or above 18 miles per hour. When the car is operated above the speed of 18 miles an hour, therefore, the contact in the governor 85 is broken, which will de-energize the solenoid coil 82 in the secondary control valve 8|, since the lead 86 will no longer be connected to the ground. When the solenoid coil 82 is deenergized, the secondary control valve 8| assumes the position shown in Figure 4, that is, the

valve I00 is unseated from the opening to the passage 94 and the valve IOI is seated against the opposite opening to the passage 94, closing the communication between said passage and the recess 93. Suction from the motor, therefore, may pass through the vacuum intensity control valve I03, pipe line I04, and into the secondary control valve 8| into another opening 9|,- passage 92, and

thence into the chamber 90. From the chamber 90 the vacuum may pass through the passage 94 into the opening 95 and thence through the pipe I02 to the main control valve.

If the driver relaxes his grasp from the steering wheel through an emergency or for any other reason, the contacts in said switch of the steering wheel I0 are broken and electrical current cannot flow from the battery 42 through 'the leads 44 and 43, solenoid coil 4|, leads 45, 46, switch 31 and lead 38, since the connection to the ground I0a is broken. The solenoid coil 4|, therefore, is de-energized and the valves 13 and 14 return to the position shown in Figures 2 and 3. The opening 51 is closed to the atmosphere by the valve 13 seating against the opening to the passage 58, closing the same to the recess 52 and opening 53. Suction enters the chamber 49 through the pipe I02, and since the valve 14 is unseated from the passage 56, the suction passes into this passage and into the opening 51, thence to the pipe 40 and into the power cylinder 30, causing the diaphragm thereon to move the shaft 29 to the left which, in turn, moves the connecting rod 25, arm 22, clevis I8 to the left, pivoting the arm I9 at I 9a, which forces the piston rod of the master cylinder inwardly applying the brakes of the vehicle. I

. The intensity of the vacuum entering the power cylinder and with which the brakes are applied is governed by the secondary control valve 8| and the vacuum intensity control valves I09 and I03. I

When the vehicle is being operated ata speed in excess of the speed at which the electrical governor 85 is set, for example, eighteen miles per hour, the contacts in the governor 85 are broken ilr wii s 2 2 leeefwgeiih lead 81 w h shown in Figure 4 of the drawings, that is, the

valve IOI is seated against one end of the passage 94, closing the same to the recess 93 and opening 91 to which is attached the pipe H0. The valve I00 is unseated from the other end of the passage 94, opening the chamber 90 thereto and-to the opening 95 to which it attached the pipe line I02, which leads to the opening 5| in the main, control valve 35.

When the grasp of the operator is released 'from the steering wheel I0 and the vehicle is being operated at more than eighteen miles per hour, suction passes from the intake manifold of the engine through the pipe 16 valve 80, check valve 19, pipe line 16, the vacuum intensity valve I03 controlled from the drivers compartment, to

admit the desired vacuum into the remainder of the system, through the line I04 into the opening 9| of the secondary control valve 8-I. The suction then passes through the passage 92 intochamber 90 of said secondary control valve; thence through the passage 94, the opening 95 into the line I02 and enters the main control valve through the opening 5|.

since the solenoid coil 4| has been de-energized by the release of the drivers grasp on the steering wheel I0, as previously described, the suction passes through the chamber 49 into the passage 55 and thence into the power cylinder 30, applying thebrakes of the vehicle at the intensity to which the valve I03 is set.

When the vehicle is being operated at eighteen miles per hour or under, the solenoid coil 82 in the valve 8| is energized by the flow of the electrical current from the battery 42, through the lead 44,

the armature therein against the opening to the I passage 94, closing communicationbetween said passage and the chamber 90. This will unseat the valve IOI from the opposite opening of the passage 94, opening communication between sai passage and the recess 93.

Therefore, whenthe car is being operated at, for example, eighteen .miles per hour orless and the drivers grasp is released from the steering wheel I0,-de-energizing the solenoid coil 4| in the valve 35, suction will pass from the intake manifold of the engine through the pipe 16, valve 80. check valve 19, pipe 16, pipe III, intensity control valve I09, which is set at a fixed position to admit the vacuum of the proper intensity for applying brakes at the lower speeds; thence through pipe II 0 into opening 91 of the secondary control valve 8| into the recess 93 therein andinto the passage 94, thence out through the Movement of the shaft 29'to the left moves the arm I40 to the left, the tension of the spring MI pulling the lever I39 to the left as the arm I46 moves in that direction until the lever I39 engages the stop I48, at which time the lever I39, using the stop I48 as a pivot point moves the rod I 34a to the right, breaking the contact in the switch I34 which breaks the connection between the lead 83a to the ignition of the vehicle and the battery 42 through the switch 83, leads I31 and I36, switch I34 and lead 44.

As soon as the motor is stopped, the brakes being applied through the automatic system, there is no longer a vacuum in the line 15, since suction from the intake manifold of the engine stops with the engine. The diaphragm in the locking device I I2 will drop which will disengage the cam I22 from the arm I24, the arm I24 pivoting forward on the fulcrum pin I25, wedging the diagonally opposite edges of the hole I26 against the shaft 29, looking the same against movement to the right which locks the brakes in an applied position.

Loss of suction in the pipe 15 through stopping of the engine also allows the diaphragm 62 in the main control valve 35 to drop, unseating the valve 68 from the passage 59. Vacuum will then flow from the auxiliary reservoir 11 through the pipe I6 into the opening 50 in the main control valve 35, thence through the passage 59 into the chamber and from the chamber 65 into the passages Ill and 69 into the opening 5|, thence into the chamber 49 through the passage 56 and into the pipe 40 through the opening 51 holding the diaphragm in the brake cylinder, so that the brakes are held in an applied position by the naximum vacuum in the automatic system, regardless of the settings on the vacuum intensity valves I03 and I09, since vacuum will pass to the power cylinder 30 from the auxiliary reservoir TI through the pipes I8 and 16, passing around the vacuum intensity valves.

If it is desired to stop the vehicle and not cut off the motor, for example, in making a conscious, as distinguished from a stop made by means of the operator losing consciousness, the clutch is depressed, moving the crank I44 to the left. The flexible connection I46 also moves to the left allowing the arm I42 to move to the left with the lever I39 as the brakes are being applied, thereby keeping the switch I34 in contact and the motor of the vehicle running.

If it is desirable to not have the ignition circuit broken through the use of the automatic braking system, for example, during city driving,

switch I34 may be rendered inoperative by closing switch I35 which will connect lead 83a to the battery 42 through the switch 63, leads I31, I36,

switch I35 and lead I38.

When the foot brake is used in the conventional manner, the extension I2 is rocked'to the on the pivot I9a, moving the piston rod 20 inwardly in the master hydraulic cylinder 2I,,ap'-

plying the brakes of the vehicle. The movement "of the extension I2 to the left will, at the same time, move the connecting rod 33 to the left,

.control valve 35 remains energized, the relaxing of the operators grasp ori the steering wheel I0 not afi'ecting'the same, since current will pass from the battery 42, lead ,iead 43 through the solenoid coil 4|, lead 45, lead 36, switch 32 and through lead 34 to the ground.

Movement of the extension I2 and clevis I6 to the left will also, at the same time, rock the arm- 22 to the left, moving the rod 25 and shaft 29 to the left. Since the solenoid coil 4! in the main control valve 35 is energized, the power cylinder 36 is open to the atmosphere through the pipe 46, opening 5], in the main control valve 35, passage 56, recess 52, opening 53, and through the air cleaner 54, which allows free movement of the shaft 29 to the left.

Thecontact in the ignition cut-cut switch I34 is not broken by movement to the left. of the shaft 29 and the arm I40 which is attached to said shaft, when the brakes are applied by foot in theconventional manner, since movement of the rod 33 to the left allows slack in the flexible connection I41, which permits movement of the arm I42 to the left, permitting the lever I39 to move to the left also through. the tension of the spring I4I,-so that the same will not pivot at the pivot point I42a to break the contact in the switch I34. The vehicle engine, therefore, will remain running when the brakes are applied by the operators foot in the conventional manner.

In the event, the automatic system for any reaa son should fail, or it is desirable to operate the lead 38 and lead 36, and the pet-cock Ila. is opened, releasing the vacuum in the system through the auxiliary reservoir "ll.

It is apparent that the specific illustrations given above have been given by way of illustration and not by way of limitation, and that the structures above described are subject to wide variation and modification without departing from the scope or intent of the invention, all of which variations and modifications are to be in cluded within the scope of the present invention.

.1 claim:

1. In combination with a motor vehicle ofthe type having a motor, a steering wheel, a source of electrical energy, a source of pressure substantially different from atmospheric, a series of brakes, and brake operating means to operate said brakes, a clutch and clutch operating means to operate said clutch; the combination there with of a device for automatically actuating said brake operating means upon release of the steering wheel by the operator of the vehicle comprisingfluid pressure operating means, an actuating' means from said fluid pressure operated means to said brake operating means, a conduit system having connections leading from said source'of pressure different from atmospheric to said fluid operated means, one of said connections beingobstructed so as to vary the pressure different 'from atmospheric transmitted thereconnections, one of said control valves being normally released to the atmosphere and adapted to admit said pressure less than atmospheric to said fluid pressure operated means upon operation of said automatically actuated brake operating means, a second of said control valves adapted to admit a pre-determined pressure less than atmospheric to said first-mentioned control valve in accordance with the speed at which the vehicle is operated when said autothrough and control valves on said one of said matic brake operating means is operated and a second connection in said conduit system leadbrake operating means upon release of the steering wheel by the operator of the vehicle comprising fluid pressure operating means, an actuating means from said fluid pressure operated means to said brake operating means, a conduit system having connections leading from said source of pressure diiferent from atmospheric to said fluid operated means, one of said connections being obstructed so as to vary the pressure different from atmospheric transmitted therethrough, and

control valves on said one of said connections,

one of said control valves being normally released to the atmosphere and adapted to admit said pressure less than atmospheric to said fluid pressure operated means upon operation of said automatically actuated brake operating means, a second of said control valves adapted to admit a pre-determined pressure less than atmospheric to said first-mentioned control valve in accordance with the speed at which the vehicle is operated when said automatic brake operating means is operated, a second connection in said conduit system leading from said source to said firstmentioned control valve to admit a maximum pressure from said source when the vehicle is at ratest, and means to prevent movement of said actuating connection when said motor stops.

3. In combination with a motor vehicle of the type having a motor, a steering wheel, a source of electrical energy, a source of pressure substantially different from atmospheric, a series of brakes and brake operating means tooperate said brakes, a clutch and clutch operating means to operate said clutch; the combination therewith .of a device for automatically actuating said brake operating means upon release of the steering wheel by the operator of the vehicle comprising fluid pressure operating means, an actuating means from saidfluid pressure operated means to said brake operating means, a conduit system having connections leading from said source of pressure different from atmospheric to said fluid operated means, one of said connections being obstructed so as to vary the pressure different from atmospheric transmitted therethrough, and control valves on said one of said connections, one of said control valves being normally released to the atmosphere and adapted to admit said pressure less than atmospheric to said fluid pressure operated means upon operation of said automatically actuated brake operating means, a second of said control valves adapted to admit a pre-determined pressure less than atmospheric to said first-mentioned control valve in accordance withthe speed at which the vehicle is operated when said automatic brake operating means is operated, a second connection in said conduit system leading from said source to said first-mentioned control valve to admit a maximum pressure from said source when the vehicle is at rest, and" means to preu vent movement of said actuating connection aieaoai whensaid source of pressure substantially different from atmospheric is stopped.

- 4. In combination with a motor vehicle of the type having a motor, a steering wheel, a source of electrical energy, a source of pressure substantially' diiferent from atmospheric, a series of brakes and brake operating means to operate said brakes, a clutch and clutch operating means to operate said clutch; the combination therewith of a device for automatically actuating said brake operating means upon release of the steering wheel by the operatorof the vehicle comprising fluid pressure operating means, an actu ating means from said fluid pressure operated means to said brake operating means, a conduit system having connections leading from said source of pressure different from atmospheric to said fluid operated means, one of said connections being obstructed so as to vary the pressure different from atmospheric transmitted therethrough, and control valves provided with electro-magnetic operating means, on said one of said connections, one of said control valves being normally released to the atmosphere and adapted to admit said pressure less than atmospheric to said fluid pressure operated means upon operation of said'automatically actuated brake operating means, a second of said control valves adapted to admit a pre-determined pressure less than atmospheric to said first-mentioned control valve in accordance with the speed at which the vehicle is operated when said automatic brake operating means is operated and a second connection in said conduit system leading from said source to said first mentioned control valve to admit a maximum pressure from said source when the vehicle is at rest.

5. In combination with a motor vehicle of the type having a motor, a steering wheel, a source of electrical energy, a source of pressure substantially diflerent from atmospheric, a series of brakes and brake operating means to operate said brakes, a clutch and clutch operating means to operate said clutch; the combination therewith of a device for automatically actuating said brake operating means upon release of the steering wheel by the operator of the vehicle comprising fluid pressure operating means, an actuating means from said fluid pressure operated means to said brake operating means, a conduit system having connections leading from said source of pressure different from atmospheric to said fluid operated means, one ofsaid connections being obstructed so as to vary the pressure different from atmospheric transmitted therethrough, and control valves on said one of said connections, one of said control valves being provided with electro-magnetic operating means adapted to be de-energized so as to admit pressure substantially less than atmospheric to said fluid pressure operated means from said source when said vehicle brakes are applied by means of said automatic brake operating means, a

second of said control valves being provided with electro-magnetic operating means adapted to be energized when the vehicle is operated at or below a pre-determined low rate of speed, and admit a pre-determined low pressure less than atmospheric to said first-mentioned control 6. In combination with a motor vehicle of the type having a motor, a steering wheel, a source of electrical energy, a source of pressure substantially difierent from atmospheric, 9. series of =brakes and brake operating means to operate means to said brake operating means, a. conduit system having connections leading from said source of pressure different from atmospheric to said fluid operated means, oneoi' said connections being obstructed so as to vary the pressure different from atmospheric transmitted therethrough, and control valves on said one of said connections, one of said control valves being provided with electro-magnetic operating means adapted to be de-energized so as to admit pressure substantially less than atmospheric to said fluid pressure operated means from said source when said vehicle brakes are applied by means of said automatic brake operating means, a sec- 0nd of said control valves being provided with electro-magnetic operating means, means to deenergize said electro-magnetic operating means when the vehicle is operated above a pre-determined low rate of speed, and admit a -pre-determined substantially high pressure less than atmospheric to said first-mentioned control valve. when said automatic brake. operating means is operated, and a second connection'in said conduit system leading from said source to said first-mentioned control valve to admit a maximum pressure from said source when the vehicle is at rest.

7.. In combination with a motor vehicle of the type having a motor, a steering wheel, a source of electrical energy, a source of pressure substantially different from atmospheric, a series of brakes and brake operating means to operate said brakes, a clutch and clutch operating means to operate said clutch; the combination therewith of a device for automatically actuating said brake operating means upon release of the steering wheel by the operator of the vehicle comprising, fluid pressure operating means, an

actuating means from said fluid pressure opersure less than atmospheric and another of said governing valves being manually set to pass a substantially high pressure loss, than atmospheric ,'control valves on said one of saidconnections, one of said'control valves being provided with electro-magnetic operating means adapted to be de-energized' so as to admit pressure substantially less than atmospheric to said fluid pressure operated means from said source when said vehicle brakes are applied by means of i said automatic brake operating means, a second of said control valves being provided with electromagnetic operating means to be energized when the vehicle is operated at or below a pre-determined low rate of speed; and admit a pre-determined low pressure less than atmospheric to said first-mentioned control valve through saidparallel pipe line governed by said governing valve set to pass a low pressure when said automatic brake operating means is operated, and at second connection in said conduit system leading from said source to said first-mentioned control valve to admit a maximum pressure from said source when the vehicle is at rest.

8. In combination with a motor vehicle of the type having a motor, a steering wheel; a source of electrical energy, a source of pressure substantially different from atmospheric, a series of brakes and brake operating means to operate said brakes, a clutch and clutch operating means to operate said clutch; the combination therewith of a device for automatically actuating said brake operating means upon release of the steering wheel by the operator of the vehicle comprising fluid pressure operating means, an actuating means from said. fluid pressure operated means to said brake operating means, a conduit system having connections leading from said source of pressure different from atmospheric to said fluid operated means, one of said connections consisting of parallel pipe lines, intensity governing valves in said pipe lines to regulate the intensity of said pressure less than atmospheric transmitted therethrough, one of said governing valves being set at a pre-determined position to pass a substantially low pressure less than atmospheric and another of said governing valves being manually set to pass av substantially high pressure less than atmospheric, control valves on said one of said connections, one of said control valves being provided with electro-magnetic operating means adapted to be de-energized so as to admit pressure substantially less than atmospheric to said fluid pressure operated means from said source when said vehicle brakes are applied by means of said automatic brake operating means a second of said control valves being provided with electro-magnetic operating means, means to de-energize said electro-magnetic operating means when the'vehicle is operated above a pre-determined low rate of speed and admit a pro-determined substantially high pressure less than atmospheric to said first-mentioned control valve through said parallel pipe line governed by said governingvalve manually set to pass a high pressurewhen said automatic brake operating means is operated, and a second connection in said conduit system leading from said source to said first-mentioned control valve to admit a maximum pressure from said source when the vehicle is at rest. J

9. In combination with a motor vehicle of the type having a motor, an ignition circuit to said motor, a steering wheel, a source of electrical energy, a 'source of pressure substantially different from atmospheric, a series of brakes and brake operating means to operate said brakes, a clutch and clutch operating means to operate said clutch; the combination therewith of a de vice for automatically actuating said brake operating means upon release of the steering wheel by the operator'of the vehicle comprising fluid pressure operating means, an actuating means from said fluid operated means to said brake operating means, a conduit system having connections leading from said source of pressure different from atmospheric to said fluid operated means, one of said connections being obstructed so as to varythe pressure different from atmospheric transmitted therethrough, and control valves provided with electro-magnetic operating means, on said one of said connections,'one of said control valves being normally released to the atmosphere and adapted to admit said pressure less than atmospheric to said fluid pressure operated means upon operation of said automatically actuated brake operating means, a second of said control valves adapted to admit a predetermined pressure less than'atmospheric to said first mentioned control valve in accordance with the speed at which the vehicle is operated when said automatic brake operating means is operated, means operable by said actuating conthe type having a motor, an ignition circuit to said motor, a steering wheel, a source of electrical energy, a source of pressure substantially diflerent from atmospheric, a series oi. brakes and brake operating means to operate said brakes, a clutch and clutch operating means to operate said clutch; the combination therewith of a device for automatically actuating said brake operating means upon release of thesteering wheel by the operator of the vehicle comprising fluid pressure operating means, an actuating means from said fluid operated means to said brake operating means, a conduit system having connections leading from said source of pressure different from atmospheric to said fluid operated means, one of said connections being obstructed so as to varythe pressure different from atmospheric transmitted therethrough, and control valves provided with eletro-magnetic operating means, on said one of said connections, one of said control valves being normally released to the atmosphere and adapted to admit said pressure less than atmospheric to said fluid pressure operated means upon operation of said automaticallycactuated brake operating means, a second of said control valves adapted to admit a pre-determined pressure less than atmospheric to said first-mentioned control valve in accordance with the speed at which the vehicle is operated when said automatic brake operating means is operated, means operable by said actuating connection to disconnect the ignition circuit of said motor when said automatic brake operating means is operated, means to render said ignition disconnecting means inoperative when clutch operated means is operated and a second connection in said conduit system leading from said source to said first-mentioned control valve to admit a maximum pressure from said source when the vehicle is at rest.

11. In combination with a motor vehicle of the type having a motor, a steering wheel, a source of electrical energy, a source of pressure substantially difierent from atmospheric, a series of brakes and brake operating means to operate said brakes, a clutch and clutch operating means to operate said clutch; the combination therewith of a device for automatically actuating said brake operating means upon release of the steering wheel by the operator of the vehicle comprising fluid pressure operating means, an actuating means from said fluid pressure operated means to said brake operating means, a conduit system having connections leading from said source oi pressure different from atmospheric to said fluid operated means, one of said connections being obstructed so as to vary the pressure different from atmospheric transmitted therethrough, and

control valves on said one of said connections,

one of said control valves being normally released to the atmosphere and adapted to admit said pressure less than atmospheric to said fluid pressure operated means upon operation of said automatically actuated brake operating means, a second of said control valves adapted to admit a pre-determined pressure less than atmospheric to said first-mentioned control valvein accordance with the speed at which the vehicle is operated when said automatic brake operating meansv of brakes, and brake operating means, including a hydraulic'cylinder, to operatesaid brakes, a clutch and clutch operating means to operate said clutch; the combination therewith of a device ior automatically actuating said brake operating means upon release of the steering wheel by the operator of the vehicle comprising fluid pressure operating means, an actuating means from said fluid pressure operated means to said brake operating means, said actuating means extending to and operating said hydraulic system, a con-,

duit system having connections leading from said source of pressure difierent from atmospheric to said fluid operated means, one of said connections being obstructed so as to vary the pressure different from atmospheric transmitted therethrough and control valves on said one of said connections, one of said control valves being normally released to the atmosphere and adapted to admit said pressure less than atmospheric to said fluid pressure operated means upon operation of said automatically actuated brakeoperating means, a second of said control valves adapted to admit a pre-determined pressure less than atmospheric to said first-mentioned control valve in accordance with the speed at which they vehicle is operated when said automatic brake operating means is operated and a second connection in said conduit system leading from said source to said first-mentioned control valve to admita maximum pressure from said source when the vehicle is at rest.

13. In combination with a motor vehicle' of the type having a motor, a steering wheel, a source of electrical energy, a source of pressure substantially diflerent from atmospheric, a series of brakes and brake operatingmeans to operate said brakes, a clutch and clutch operating means to operate said clutch; the combination therewith of a device for automatically actuating said brake operating means upon release of the steering wheel by the operator of the vehicle comprising fluid pressure operating means, an actuating means from said fluid pressure operatw means to said brake operating means, a conduit system having connections leading from said source of pressure diiferent from atmospheric to said fluid operated means, one of said 75 connections being obstructed so as to vary the pressure different from atmospheric transmitted therethrough, and control valves on saidone of said connections, one of said control valves being normally released to the atmosphere and adapted to admit said pressure less than atmospheric to said fluid pressure operated means upon operation of said automatically actuated brake operating means,. a second of said control valves adapted to admit a pre-determined pressure less than atmospheric to said first-mentioned control valve in accordance with the speed -at which the vehicle is operated when said automatic brake operating means is operated, a second connection in said conduit system leading from said source to said first-mentioned control valve ,to admit a maximum pressure from said source when the vehicle is at rest, a locking device adapted to act upon said actuating connection comprising a casing having a diaphragmv chamber, a diaphragm in said chamber, a port admitting said pressure substantially less than atmospheric to one side of said diaphragm, a latch means with a hole intermediate its length extending around said brake actuating connection, one end of said latch means being pivoted,

the opposite end having an offset surface, a cam connected to said diaphragm to act upon said ofiset portion and hold the diagonally opposite edges of said hole from engaging said actuating connection when pressure substantially less than atmospheric is exerted on said diaphragm, and to disengage said offset portion when said pressure is stopped permitting the diagonally opposite edges of said hole to engage and lock said brake actuating connection against movement.

14. In combination with a motor vehicle of the type having a motor, a steering wheel, a source of electrical energy, a source of pressure substantially diflferent from atmospheric, a serles of brakes and brake operating means to operate said brakes, a clutch and clutch operating means to operate said clutch; the combination therewith of av device for automatically actuat-v ing said brake operating means upon release of the steering wheel by the operator of the vehicle'comprising fluid pressure operating means,

an actuating means from said fluid pressure operated means to said brake operating means, a conduit system having connections leading from said source of pressure diflerent from atmospheric to said fluid operated means, one of said connections being obstructed so as to vary the pressure difl'erent from atmospheric transmitted therethrough, and control valves on said one of said connections, one of said control valves being normally released to the atmosphere and adapted to admit said pressure less than atmospheric to said fluid pressure operated means upon operation of said automatically actuated brake operating means, a second of said control valves adapted to admit a pre-determined pressure less than atmospheric to said first-mentioned control valve in accordance with the speed at which the vehicle is operated when said automatic brake operating means is operated, a second connection'in said conduit system leading from said source to said first-mentioned control valve to admit a maximum pressure from said source when the vehicle is at rest, a locking device adapted to act upon said actuating connection comprising a casing having a diaphragm chamber, a diaphragm in said chamber, a port admitting said pressure substantially less than atmospheric to one side of said diaphragm, a latch means with a hole intermediate its length extending around said actuating connection, one end of said latch means being pivoted, the opposite end having an offset surface, a cam connected to said diaphragm to act upon said offset portion and hold the diagonally opposite edges of said hole from engaging said brake actuating connection when pressure substantially less than atmospheric is exerted on said diaphragm, and to disengage said offset portion when said pressure is stopped permitting the diagonally opposite edges of said hole to engage and lock'said brake actuating connection against movement, and unlocking means mounted on said casing to unlock said latch from said actuating connection independently or the pressure less than atmospheric.

WARREN 1..

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